In 1993, Dr. Gregory McDonald had one of the most horrific experiences of his career—helping investigate more than 110 heat-related deaths over a span of 10 days—the result of a July heatwave that had gripped Philadelphia.
McDonald, who currently serves as dean of PCOM’s School of Health Sciences and as director of the MS in Forensic Medicine program, was working at the Philadelphia Medical Examiner's Office (MEO) at the time. The deaths were well in excess of the typical number of homicides, suicides and other fatalities that would be expected during a comparable time period. He likened the death toll to a mass casualty situation.
“You can imagine that a plane crash in which 110 people died would certainly get the attention of people,” he said.
For McDonald and his fellow investigators at the Philadelphia MEO, the particularly attention-grabbing aspect was that many of the deaths may have been preventable.
When assessing the impact of excessive heat or a heatwave, the number of deaths attributable to hyperthermia is a key indicator. An unusual element of the heatwave of 1993 was that most of the heat-related deaths did not meet the strict criteria of clinical hyperthermia. Hyperthermia, McDonald explained, occurs when the body’s temperature exceeds 104 degrees Fahrenheit. It can encompass a range of symptoms including muscle cramps, fatigue, dizziness, mental confusion, organ failure and more.
“There’s a spectrum of how these progress,” he said.
When a person is observed with symptoms of heat-related illnesses, medical intervention may prevent adverse outcomes. For individuals living alone, help may not be readily available.
According to McDonald, the elderly are particularly at risk.
“They lack some of the thermoregulatory factors that can tell them when they're getting too hot,” he said. “By the time they realize it, they’re already compromised.”
Many of the heatwave victims were found several days after they died and had other commonalities—advanced age, preexisting medical conditions and lack of access to a adequately cooled environment. Several of the victims lived in row homes.
“I grew up in a row home in Philadelphia and literally it's like an oven,” McDonald said.
Inside temperatures can get very high due to the black tar roofs and lack of cross ventilation. Oftentimes, there is little or no shade. In more dangerous parts of the city, residents may keep the windows closed in an attempt to prevent criminal activity. For the elderly—especially those on fixed incomes—this can be very dangerous.
“Maybe they can't afford air conditioning,” he said. “Even fans, they help move some air around but sometimes it just makes a convection oven. So then you have people, they can't get out. They can't hydrate. they start to lose electrolytes, especially if they're shut-ins or there's not someone checking on them.”
McDonald and other investigators from the Philadelphia MEO made note of numerous other factors that could have contributed to the deaths including medication use, obesity and alcohol consumption.
“All those things together can be very difficult to deal with, especially for a compromised population,” he said. “But again, most of those did not meet these strict criteria of hyperthermia.”
From a public health perspective, not being able to attribute the deaths to hyperthermia was a problem.
“In forensics, when you list an environmental condition, like cold or heat, that takes it out of the realm of a natural death and puts it into the category of an unnatural death,” he said. That information is added to the death certificate and can give public health officials hard data they can use to enact preventative measures.
The forensic investigators at the Philadelphia MEO realized they needed to categorize the heat-related deaths in a way that better highlighted the risk posed by extreme heat. By studying the excess deaths during the heatwave, they were able to determine demographic characteristics and validate the criteria they used to classify a death as heat-related. The findings, published in The American Journal of Forensic Medicine and Pathology, listed the criteria for classifying a death as heat-related as including “a frail, elderly decedent with or without known preexisting disease or a younger decedent with evidence of preexisting acute or chronic illness and substantial environmental or circumstantial evidence of heat as a contributing factor to death (i.e., the decedent is found in a hot environment without cooling devices, and with windows closed).”
As a result of the work done by McDonald and other death investigators at the Philadelphia MEO, public health measures were put in place to help prevent future heat-related deaths. These measures included efforts to increase public awareness about the dangers of excessive heat and providing susceptible populations with access to shelters or other air-conditioned locations. In the mid-90s, McDonald was part of a task force that used data collected on death certificates to identify populations to proactively reach out to in the event of a heatwave.
This, McDonald explained, is just one example of the important role medical examiners and coroners play in improving public health.
“We’re the unsung heroes,” he said. “People have a perception of us that we only deal with dead people, that we have no impact on the living and I do think that’s a mistake. We’re not only a voice for the dead, we can help the living as well.”
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